Adipose tissue was obtained by needle biopsy from cystic fibrosis (CF) patients and appropriate controls. Adipocytes were incubated in Krebs-Ringer buffer with 2% bovine serum albumin and 5mM glucose for 2 hours. Basal lipolysis and lipolytic response to isopreterenol and to theophylline were virtually identical for adipocytes and controls. In a separate investigation adipose tissue was obtained from rat epidydimal pads and human surgery samples to establish a micro-system from preparing fat cell membranes and for measuring adenyl cyclase activity in these samples. Adipose tissue from CF and normal subjects was obtained thru a needle biopsy. The preliminary results show that adenyl cyclase from CF fat cell membranes appear to be more sensitive to stimulation by the diterpene, Forskoline. On the other hand, adenyl cyclase sensitivity to isoproterenol and epinephrine appear to be indistinguishable in CF and normal subjects.